The disclosure is related to an assembly for a retractable thruster for attachment to a maritime vessel.
Examples of retractable thrusters for vessels may be found in the following issued patents and printed publications. U.S. Pat. No. 3,807,347 A by Baldwin discloses an assembly, particularly an auxiliary power source, for sailboats. A propeller is connected to a shaft extending through an aperture in the hull to a drive unit which supplies propulsion power to the propeller. The propeller is lowered into the water and retracted into the hull, respectively, via a flexible cable actuated manually from the top of the sailboat.
EP 2 210 809 A2 by Klingenburg GMBH discloses a thruster that is movable upwards and downwards in an out of the thruster housing, by means of a threaded rod rotated by an external drive means. The thruster itself is arranged rotary about a vertical axis to enable the vessel to be moved in the desired direction by the thruster.
NL 1 020 217 C1 by Wouter Steusel discloses an electrically driven propeller device especially developed for sailboats. A housing accommodates a control drum arranged rotary and vertically displaceable therein. A propeller system is arranged at the lower end of the housing and driven by a first drive means to advance the vessel in the water. A second drive means is arranged at the top to enable rotation of the propeller system about its vertical axis to move the vessel in the desired direction.
EP 2 657 127 A1 (Beacon Finland LTD OY) relates to a retractable thruster comprising a rack and pinion drive to enable vertical movement of the thruster and allow service operations to be performed on the propeller driver also when the thruster is retracted.
CN 202054138 U (NANTONG ZHENHUA HEAVY EQUIPMENT MFG CO LOTD) discloses a retractable propeller driven by a permanent magnet motor and further comprises guiding rods, traverse rods, and several motors.
EP1959163 discloses a combined linear and rotary actuator for a retractable thruster having a shaft with a screw thread, a nut engaging the screw thread, and engaging means movable between a first location where rotation of the turning mechanism produces substantially linear displacement of the shaft, and a second location where rotation of the turning mechanism produces substantially rotary displacement of the shaft.
WO2009014296 discloses an icebreaking additional propulsion system including at least one retractable thruster capable of vertically moving into and out of the hull of a ship. The retractable thruster includes a pair of guide rods vertically installed within the hull, a column vertically movable along the guide rods, a drive unit mounted to an upper end of the column for vertically moving and swiveling the column, and a propeller attached to a lower end of the column for generating propelling power.
U.S. Pat. No. 5,522,335 discloses an auxiliary thruster for a marine vessel including a submersible propulsion unit which has a shroud with a propeller rotatably mounted therein. Further, it describes a propulsion unit deploying and rotating mechanism mounted on the hull and on the propulsion unit operable to extend the propulsion unit out of the hull and retract it into the hull and to rotate the propulsion unit to direct the thrust generated thereby in any desired direction when the thruster is in the deployed position. When the thruster is retracted, it is positioned with a tunnel extending transversely through the hull. Rotation of the propeller while in the retracted position generates laterally directed thrust through the tunnel.
WO2011031158 discloses a retractable thruster assembly comprising: a thruster head with a propeller, a casing structure vertically guided in the thruster well, the casing structure having a lower end portion to which the thruster head is mounted so as to extend below the casing structure, the casing structure including a watertight compartment, and an electric propeller drive motor being housed in said compartment. The thruster assembly is vertically displaceable between an operative extended position, in which the thruster head projects downward beyond the bottom plane of the hull, and a retracted position, in which the thruster assembly is raised and the thruster head is received with the thruster well.